Sulfonate detergent compositions



rates 'SULFONATE DETERGENT COMPOSITIONS Henry Y. Lew, San Francisco, Calif., assignor to California Research Corporation, San Francisco, Calif., a corporation of Delaware Filed Mar. 22, 1955, Ser. No. 496,079

5 Claims. (Cl. 252-161) No Drawing.

Alkyl benzene sulfonate detergents, such as are pro-' duced in the art by sulfonating C C monoalkyl benzenes which have been obtained either by condensing chlorinated paraffins with benzene in the presence of a Friedel-Crafts catalyst, or by alkylating benzene with long branched-chain olefins or Olefin polymers having a branched-chain structure, as in polypropylene, likewise in the presence of a suitable catalyst, e.g., HF, are widely employed by laundries and in homes because of their excellent soil-removal characteristics.

However, the foam performance of these sulfonate detergents during the washing of soiled clothes and fabrics is far from being as satisfactory as their ability to remove soil. As a matter of fact, although C -C branchedchain monoalkyl benzene sulfonates when present in dilute aqueous solutions in the bowl of a washing machine produce relatively large amounts of suds, these suds are extremely unstable, lacy in texture, and readily break down and disappear under agitation and in contact with soil. This inability to produce stable, statisfactory suds represents a drawback in the eyes of a large'fraction of thefconsumer public who are not only accustomed to a high, creamy foam of conventional fatty acid soaps and. expect the same kind of foam from synthetic detergents, V

but frequently consider the foam to be an index of the washing efliciency and a measure of the quantity of powdered soap or synthetic detergent required for efficient washing. v

A large number of additives thought likely to improve the foam performance of branched-chain alkyl benzene sulfonate detergents has been proposed in the past Without succeeding, in most cases, to secure satisfactory foam characteristics and, in particular, to secure a greater foam stability and a better foam quality, i.e., a texture approximating that of conventional soapsuds. Besides, many of these proposed additives were relatively expensive and their inclusion in alkyl benzene sulfonate detergent formulations tended to increase unduly the ultimate sales price of these formulations.

Thus, the search for new, inexpensive and efficient foam-improving agents for alkyl benzene sulfonate detergents continued on unabated.

I have now discovered that by combining detergent branched-chain C C monoalkyl benzene sulfonates with effective proportions of a long straight-chain C C hydrocarbon sulfonate and an alcohol from the group consisting of C C straight-chain saturated alcohols and straight-chain C -C alkane 1,2-glycol detergent formulations can be prepared which, upon being dissolved in water to form dilute solutions of 0.1 to 0.4% concentration, conventional in laundry practice, produce stable, good-quality, persistent suds. As shown later in this specification, the two-component combination of a detergent branched-chain alkyl benzene sulfonate and a longstraight-chain hydrocarbon sulfonate is incapable of producing suds of good stability and quality. On the other hand, the addition of a C C straight-chain saturated aliphatic alcohol, or'a straight-chain C C alkane 1,2- glycol, to the detergent branched-chain alkyl benzene sulfonate, while stabilizing the foam of this latter, provides but an inadequate volume of the foam. In fact, the alcohol tends to act as a defoamer and to decrease the formation of foam. It is, therefore, entirely unexpected that the three-component combination of a detergent branched-chain alkyl benzene sulfonate, a long straightchain hydrocarbon sulfonate, and a Cpl-C1 straight-chain saturated aliphatic alcohol, or a straight-chain C .,C alkane 1,2-glycol, is capable of producing a stable, goodquality, and persistent foam.

In the aforementioned three-component combination, the long straight-chain C C hydrocarbon sulfonate can be present in amounts ranging from about 5 to about 50% by weight, whereas the alcohol or 1,2-glycol component can be present in amounts ranging from about 2 to about 15% by weight, the balance to make up by weight being the detergent branched-chain alkyl benzene sulfonate. More aliphatic alcohol or glycol in proportions up to 25% by weight may be added, if it is desired, to increase the opacity, whiteness, and bulk density and volume of the foam.

Any suitable effective detergent water-soluble salt of a branched-chain C C monoalkyl benzene sulfonic acid, e.g., an alkali metal, an alkaline earth metal, an ammonium, an alkyl ammonium, and an alkylol ammonium sulfonate may be employed. Water-soluble C C monoalkyl benzene sulfonates such as are described in US. Patent 2,477,383 to Lewis and keryl benzene sulfonates described in U.S. Patent 2,218,472 to Kyrides are usually preferred. Particularly satisfactory, owing to their excellent soil-removing ability, are branched-chain C C monoalkyl benzene sulfonates, such as polypropylene benzene sulfonates. Employment of such sulfonate detergent materials made up of predominantly C polyproylene benzene sulfonates is found to be particularly effective, resulting in an enhanced volume of stable, goodquality foam.-

The long straight-chain hydrocarbon sulfonates effectively employed in the three-component combination of the present invention are water-soluble alkane sulfonates in which the hydrophobic alkane portion is a straight chain C -C alkyl radical attached to the sulfonic acid group by the terminal carbon. This alkyl radical may be, furthermore, substituted in the position 1 or 2 (aor [3-) to the sulfonic acid group as follows: carboxy-groups may be attached in the position 1 (a-), while sulfo-, hydroxy-, and nitrogroups may be introduced in the position 2 (13-) to the sulfonic acid.

The efiective foam-stabilizing alcohols of the detergent composition of the present invention are straightchain saturated Cp -C1 alcohols and straight-chain C -C alkane 1,2-glycols (C -C alkanols and C C alkane 1,2-diols).

If desired, a fatty acid alkylolamide such as lauric ethanolamide, lauric isopropanolamide' or lauric glycerylamide may be added to the three-component combination of this invention in amounts which may range from about 2 to about 25% by weight thereof.

The improved foam characteristics of alkyl benzene sulfonate detergent compositions formulated in accordance with the invention are not affected adversely by the presence of conventional water-soluble inorganic salt builders, i.e., neutral salts of strong inorganic acids, such as sodium chloride, potassium chloride, sodium sulfate,

and the like, and alkaline salts of weak inorganic acids,

such as sodium carbonate, tetrasodium pyrophosphate, sodium tripolyphosphate, sodium silicate, borax, and the like. From 60 to 90 parts by weight of these inorganic salt builders, preferably as sodium salts, may be present in each 100 parts by weight of a detergent formulation containing the three-component combination of the present invention.

If so desired, other conventionally employed additives such as anti-caking agents, optical blcaches, corrosion inhibitors, e.g., sodium silicate, perfume and dyes, may be added in small amounts to the formuiation. Carboxymethyl cellulose or celluronic acid salts also may be employed in small amounts to prevent redeposition of the soil. Likewise, N-alkyl glycines and diglycines C -C polypropylene benzene sulfonate was employed as a typical monoalkyl benzene sulfonate detergent component. A number of representative sodium salts of normal C -C alkane sulfonates were combined therewith together with effective proportions of a normal aliphatic C -C alcohol or a normal C -C alkane 1,2- glycol. Detergent builders were present in the following amounts: 30 parts by weight of sodium tripolyphosphate, 20 parts by weight of tetrasodium pyrophosphate, 5 parts by weight of commercial liquid N sodium silicate, and the remainder to make up 100 parts by weight was sodium sulfate.

The particles of the detergent formulation were dissolved in soft water obtained from the laboratory tap may be added to prevent occurrence of skin rashes and 15 and having a hardness of 50 p.p.m., calculated as calcium erythemas. All of these additives are introduced in comcarbonate and magnesium carbonate in a weight ratio paratively small amounts, rarely exceeding 5% by weight of 2:1. The temperature of the 0.15% solution was based on the total amounts of solids in the formulation, 120 F., and in each test run 500 ml. thereof was placed and in all events in such amounts as not to interfere with in a two-liter beaker. The solutions were tested at the the improvement of foam performance in accordance 2O bench by agitating the contents of the beakers with the with the invention. aid of propeller-type stirrers for one minute, whereupon Ordinarily, the blending of these several components foam height in millimeters was measured and the foam of the improved detergent composition of the present quality and foam stability were observed. Fifteen invention is carried out in a straightforward manner by minutes after agitation the foam height, quality and mixing the components to form a solution or slurry, drystability were again observed. The stability was rated ing this slurry to the solid particle-form; or, if so desired, by observing the rate of foam decay under mechanical evaporating it to form a paste; or, yet, diluting it to stress as by blowing on a small volume of foam gently produce a liquid concentrate. with air. A foam that withstands being blown upon Foam evaluation bench tests were carried out at the without collapse of surface bubbles has Good stability. laboratory on aqueous wash solutions of the detergent A foam having poor stability rapidly collapses when formulations prepared in accordance with the present blown upon. Intermediate stabilities are rated as Fair. invention. In these tests, each 100 parts by weight of A foam characterized by Good quality is made up of a solid, dried, particulate detergent composition conuniformly small-sized, dense-bodied bubbles of high bulk tained from 20 to 24 parts by weight of the active threes sity- This foam is White and p q Foam of component combination of the invention. Sodium Poor quality displays large-sized bubbles, has a low Branched- Foam Height Chain Saturated in mm. Test Long-Straight-Chain Alkane Parts Alkyl Aliphatic Parts Foam Run Sulfonate (as Na salt)- by Benzene Alcohol by Sta- Foam No. Name Weight Sulfonate O0mponent Weight bility Quality Detergent Name After After inParts lMin. 15 Min. by Weight 20 None 87 68 Peon-.. Poor. 20 n-Hexadecanol 2 78 12 do Fair. 20 n-Hexadecane 4 83 52 0..... Poor.

1,2-glyeol. None N 16 10 -do Do. None n-Hexadecanol 2 10 8 Fair..." D0. 10 .do 2 36 28 Good--- Good. 10 None 25 Poor Fair. 10 n-Hexadecanol 2 56 46 Good--- Good 15 None 85 57 Poem--. Poor. 15 n-Hexadecanol.. 1 83 66 Good--- Good 12 n-Dodecanol 4 37 7 Poor.... Poor;

n-Octadecane 15 -..do 2 80 66 do... Do.

Sulfonate.

5 15 n-Tetradeeanol. 2 G8 58 Fair-.... Fair. 5 15 n-HexadecanoL--. 2 78 66 Good--. Good 5 15 n OotadecanoL.- 2 68 26 Poor-. Poor. 10 10 Mixed 0 -0 1 2 78 64 Good.... Good.

elkane1,2- glycols. 6 14 n-Hexadecanol 2 85 73 do Do. 10 10 -do 2 65 54 do- Do. 10 10 n-Tetradecanol 2 23 22 0..... Fair. 10 10 n-Hexadeeanol-- 2 52 47 do Good 3 12 ..do 2 84 67 do.. Do. 5 10 n-Hexadeeanol 2 70 58 .-do....- Do. alkane sulfonates. 23 a-Sulfostearate 1O 10 -do 2 38 28 .--d0 D0. 24. 1O 10 None 36 i2 Peon--. Poor 25 2 16 n-Hexadeeano1-. 2 87 26- do 3 17 o 2 72 27 n-Hexadecane 1,2-disulfonate 10 10 Mixed G -Oz: 2 SO alkane1,2- glyeols. 28 Mixture of 0 -0 alkane 10 10 n-Hexadeeanol..-. 2 46 43 ...do-. Do.

l,2 disulionates. 29 n-Hexadeeane1,2-disulfonate 10 10 Mixed C -C 2 60 50 POOL.-- Poor.

alkane1,3 glycols. 30 Mixture of 0 -0 nlkane 16 10 n-Dodecanol 2 70 58 Fair..-" Do 1,2-disulfonates. 31 n-Octadecane1,2-disu1fonete. 10 10 n-qexailecane 1,2- 2 76 62 Good-... Good.

gyco.

Further contained 1% by weight of lauric isopropanolamide.

bulk viscosity, and tends to be lacy. It is, furthermore, grayish in color and relatively transparent. Foams intermediate in quality between Poor and Good are rated to be Fair.

The data from these representative test runs are tabulated in the preceding table.

In the table, run No. 1 shows that branched alkyl benzene sulfonate detergent produces foam which, although possessing considerable volume, utterly lacks stability and quality, and, consequently, will not persist under agitation in the presence of soil.

Runs Nos. 2 and 3 show that addition of C -C saturated aliphatic alcohols, or C -C alkane 1,2-glycols, is incapable of providing stability for the foam of branched alkyl benzene sulfonate detergents.

Run No. 4 indicates that normal C -C alkane sulfonates are incapable of forming a substantial volume of suds which, furthermore, lack quality and stability.

Run No. 5 shows that the addition of (314-016 saturated aliphatic alcohols fails to improve the quality of the foam of a normal C -C alkane sulfonate; besides, the volume of foam is so low that the slight improvement in stability is inadequate to insure foam persistence under agitation.

Runs Nos. 7, 9 and 24 illustrate the fact that twocomponent mixtures of branched-chain alkyl benzene sulfonate detergents with different normal C -C alkane sulfonates are incapable of producing stabilized suds which would persist throughout the complete washing cycle in the bowl of a washing machine.

In contrast to the aforementioned runs, test runs Nos. 6, 8, 10, 13, 14, 16, 17, 18, 19, 20, 21, 22, 23, 25, 26, 27, 28 and 31 clearly demonstrate the ability of the active three-component combination of the present invention to create adequate suds of fair to good stability and quality, which persist throughout the washing operation.

Runs Nos. 11, 12, 15 and 30 confirm the fact of inadequacy of saturated aliphatic alcohols other than those containing from 14 to 16 carbon atoms.

Run No. 29 is given to point out the criticality of the 1 (a-) and 2 3-) positions of the hydroxyl groups of the C -C alkane glycol foam stabilizers. The 1,3- glycol is inefiective as a foam-stabilizing additive.

The detergent formulations prepared in accordance with the invention are highly effective in laundering operations in automatic and non-automatic agitator-type washing machines, their dilute solutions maintaining a persistent level of good quality suds in the machine throughout the complete washing cycle of at least 20 minutes and providing a satisfactory detergency, i.e.,

efiectively removing the soil from dirty laundry when employed in concentrations of 0.1 to 0.4, common to laundry practice.

The improvement in the foam performance of detergent compositions containing active branched-chain alkyl benzene sulfonates, when formulated in accordance with the invention, is entirely unexpected, particularly in view of the fact that neither n-dodecanol, mentioned in the prior art as a foam stabilizer, nor the lower molecular weight saturated aliphatic alcohols, such as decanol,

octanol, etc., nor the higher molecular weight saturated aliphatic alcohols containing 18 and more carbon atoms, e.g., octadecanol, etc., are found capable of improving the foam stability of these sulfonate detergent formulations. In fact, these alcohols tend to act as defoamers.

I claim:

1. A detergent composition consisting essentially of, by weight, 10 to 40% active organic detergent material and to water-soluble inorganic salt detergent builders, said organic detergent material consisting essentially of, by Weight, (a) 40 to 50% branched-chain C C monoalkyl benzene sulfonate detergent; (b) 5 to 10% of a normal alcohol selected from the group consisting of C14-Cm primary saturated monohydric alcohols and C -C alkane, 1,2-glycols; and (c) 10 to 50% of a sulfonate characterized by a straight chain C -C alkyl radical attached to the sulfonic acid group by the termi nal carbon, selected from the class consisting of normal alkane sulfonates and the a-carboxy, fi-sulfo, B-hydroxy, and fi-nitro substituted derivatives thereof.

2. A detergent composition according to claim 1 wherein the sulfonate is a normal alkane sulfonate.

3. A detergent composition according to claim 1 wherein the alcohol is a saturated primary normal C C monohydric alcohol.

4. A detergent composition according to claim 1 wherein the alkane sulfonate and the alkylbenzene sulfonate are sodium sulfonates.

5. A detergent composition according to claim 4 wherein the alkylbenzene sulfonate is a C C alkylbenzene sulfonate.

References Cited in the file of this patent UNITED STATES PATENTS Kreps et a1. June 18, 1957 

1. A DETERGENT COMPOSITION CONISTING ESSENTIALLY OF, BY WEIGHT, 10 TO 40% ACTIVE ORGANIC DETERGENT MATERIAL AND 60 TO 90% WATER-SOLUBLE INORGANIC SALT DETERGENT BUILDERS, SAID ORGANIC DETERGENT MATERIAL CONSISTING ESSENTIALLY OF, BY WEIGHT, (A) 40 TO 50% BRANCHED-CHAIN C9C18 MONOALKYL BENZENE SULFONIC DETERGENT, (B) 5 TO 10% OF A NORMAL ALCOHOL SELECTED FROM THE GROUP CONSISTING OF C14-C16 PRIMARY SATURATED MONOHYDRIC ALCOHOLS AND C14-C22 ALKANE, 1,2-GLYCOLS, AND (C) 10 TO 50% OF A SULFONATE CHARACTERIZED BY A STRAIGHT CHAIN C10-C24 ALKYL RADICAL ATTACHED TO THE SULFONIC ACID GROUP BY THE TERMINAL CARBON, SELECTED FROM THE CLASS CONSISTING OF NORMAL ALKANE SULFONATES AND THE A-CARBOXY, B-SULFO, B-HYDROXY, AND B-NITRO SUBSTITUTED DERIVATIVES THEREOF. 